[
https://issues.apache.org/jira/browse/SPARK-23246?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
MBA Learns to Code updated SPARK-23246:
---------------------------------------
Summary: (Py)Spark OOM because of iteratively accumulated metadata that
cannot be cleared (was: (Py)Spark OOM because of metadata build-up that cannot
be cleaned)
> (Py)Spark OOM because of iteratively accumulated metadata that cannot be
> cleared
> --------------------------------------------------------------------------------
>
> Key: SPARK-23246
> URL: https://issues.apache.org/jira/browse/SPARK-23246
> Project: Spark
> Issue Type: Bug
> Components: PySpark, Spark Core, SQL
> Affects Versions: 2.2.1
> Reporter: MBA Learns to Code
> Priority: Critical
>
> I am having consistent OOM crashes when trying to use PySpark for iterative
> algorithms in which I create new DataFrames per iteration (e.g. by sampling
> from a "mother" DataFrame), do something with such DataFrames, and never need
> such DataFrames ever in future iterations.
> The below script simulates such OOM failures. Even when one tries explicitly
> .unpersist() the temporary DataFrames (by using the --unpersist flag below)
> and/or deleting and garbage-collecting the Python objects (by using the
> --py-gc flag below), the Java objects seem to stay on and accumulate until
> they exceed the JVM/driver memory.
> Please suggest how I may overcome this so that we can have long-running
> iterative programs using Spark that uses resources only up to a bounded,
> controllable limit.
>
> {code:java}
> from __future__ import print_function
> import argparse
> import gc
> import pandas
> import pyspark
> arg_parser = argparse.ArgumentParser()
> arg_parser.add_argument('--unpersist', action='store_true')
> arg_parser.add_argument('--py-gc', action='store_true')
> arg_parser.add_argument('--n-partitions', type=int, default=1000)
> args = arg_parser.parse_args()
> # create SparkSession (*** set spark.driver.memory to 512m in
> spark-defaults.conf ***)
> spark = pyspark.sql.SparkSession.builder \
> .config('spark.executor.instances', '2') \
> .config('spark.executor.cores', '2') \
> .config('spark.executor.memory', '512m') \
> .enableHiveSupport() \
> .getOrCreate()
> # create Parquet file for subsequent repeated loading
> df = spark.createDataFrame(
> pandas.DataFrame(
> dict(
> row=range(args.n_partitions),
> x=args.n_partitions * [0]
> )
> )
> )
> parquet_path = '/tmp/TestOOM-{}Partitions.parquet'.format(args.n_partitions)
> df.write.parquet(
> path=parquet_path,
> partitionBy='row',
> mode='overwrite'
> )
> i = 0
> # the below loop simulates an iterative algorithm that creates new DataFrames
> in each iteration (e.g. sampling from a "mother" DataFrame), do something,
> and never need those DataFrames again in future iterations
> # we are having a problem cleaning up the built-up metadata
> # hence the program will crash after while because of OOM
> while True:
> _df = spark.read.parquet(parquet_path)
> if args.unpersist:
> _df.unpersist()
> if args.py_gc:
> del _df
> gc.collect()
> i += 1; print('COMPLETED READ ITERATION #{}\n'.format(i))
> {code}
>
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
